Investors on Wall Street are celebrating and not just because it's Friday and that Cinco De Mayo is coming up, of course. So, but better jobs report is pushing stocks higher into record territory. The Labor Department says the economy added 165,000 jobs last month. The unemployment rate dipped to 7.5 percent.

Alison Kosik is at the New York Stock Exchange. Alison, the Dow was above 15,000 at one point. How are the markets doing right now?

ALISON KOSIK, CNN BUSINESS CORRESPONDENT: It was at 15,000 and a little above that. It's right now bumping up against that 15,000 level. Look, it's still hitting -- it's hitting that mark. It's making history and so is the S&P 500 making history of its own at a level we haven't seen before. And we'd like to watch the S&P 500, Jake, because even though it doesn't get all the headlines, the S&P 500 hitting this milestone is actually a bigger deal, believe it or not, because the S&P includes 500 stocks instead of just 30. And all of this happening because of what you said, that upbeat jobs report showing employers added 165,000 jobs in April. The unemployment rate dipping to 7.5 percent. All of that's pushing investors to buy in.

Kind of icing on the cake as well as the February and March numbers, those job numbers were revised higher. One analyst puts it this way saying, it shows the economy is resilient, just not robust. So the jobs picture isn't quite bright enough to push the Federal Reserve out of the mix which means its stimulus is expected to continue. That is helping to push the market even higher -- Jake.

TAPPER: Wall Street likes the jobs report, but what does it mean for you and your personal economy? Ahead this hour, Christine Romans will have the story behind the numbers including a look at where those 165,000 jobs were added in the economy.

Now to the Boston bombings. Authorities expect to file a death certificate today. We should soon learn exactly what killed suspected bomber Tamerlan Tsarnaev. The hearse you see here in this image is believed to have taken his body to a funeral home yesterday. So now, the Massachusetts medical examiner is allowed to release the official cause of death. A funeral for the 26-year-old suspect will be held in Worcester, Massachusetts, just outside Boston. That's according to the Worcester mayor's office.

And we're hearing from a law enforcement official who says the bombs used in the attack were built in the apartment Tamerlan Tsarnaev shared with his wife and little girl. And that the marathon was not the original target of the terrorists plan. That law enforcement source who is regularly briefed on the investigation says the suspects initially planned to carry out a suicide attack on the fourth of July.

Deborah Feyerick joins us live from Boston. Deb, what more have we learned about this supposed plan to strike on Independence Day? And is there any evidence to support that?

DEBORAH FEYERICK, CNN NATIONAL CORRESPONDENT: Well, right now investigators are looking into this theory that, in fact, it may have been July 4th, but there is still sort of an absence of hard evidence to suggest that, in fact, that was their number one target. Why they decided to change their plans. You know, Initially we heard reports that they were building the bomb and they built it too quickly. They didn't realize how fast they would be able to build it. And so, they sort of moved up their plan to attack the Boston marathon.

But people that I'm speaking to say they just don't believe that that's true because of the way they executed it in terms of what they call the trade craft, the way they sort of approached their target points, the time in between the detonations, the way that this whole thing was done pretty methodically suggested that there was more training involved than, gee, hey, we're done, let's go bomb the marathon.

So, you know, investigators are tracking down hundreds of leads at this point. One of them, actually just now, Jake, we can tell you, up at the University of Massachusetts Dartmouth, they've got investigators who are on the scene. They've got FBI, ATF who are checking out a couple of public areas, we have just been told. They're looking -- there were reports of loud explosions that had been taking place there over the course of a couple of months.

And so, they're going to check that out to see whether perhaps it may have been an area where they were detonating or testing the devices. So, that's pretty much what we know in terms of the location and the targets. But the folks that I'm talking to really do believe that the Boston marathon was, in fact, their intended target -- Jake.

TAPPER: And, Deb, we've also learned some new details about where law enforcement officials believe the bombs were made. What can you tell us about that?

FEYERICK: Well, now they're looking at the possibility that, in fact, the bombs were built in the home that Tamerlan Tsarnaev shared with his wife and their daughter, their young daughter. Also, Dzhokhar Tsarnaev spent a lot of time at that apartment as well. Bomb residue, I'm being told, was found both at the kitchen table as well as the kitchen sink and then the bathtub.

And we were talking about this earlier, Jake, you and I, and that is that, look, these bombs -- the ingredients you need to build these bombs are rather crude. The technical expertise to actually make them successful, well, that's a little bit different. But it's not, for example, you think of a bomb factory perhaps the attack on the First World Trade Center, the big vats of chemicals that were needed. These are pretty simple basic ingredients that you can -- you can fit in a couple bags -- Jake.

TAPPER: All right. Deborah Feyerick, thank you so much.

In California, a dangerous situation is getting more dangerous by the minute. Several big wildfires are still spreading as the winds pick up. One of them in Ventura County near Los Angeles has burned more than 10,000 acres and threatens 4,000 homes.

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UNIDENTIFIED FEMALE: Stay until I know that our house is still here.

UNIDENTIFIED MALE: As long as our family and our dogs are safe, we can get through this.

UNIDENTIFIED FEMALE: Now, we're getting those hot long days, winds and the low humidities and this stuff is just ripe and ready to burn.

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TAPPER: CNN's Stephanie Elam is along the front lines in Ventura County. And our Chad Myers is also keeping track of the fires in the CNN Weather Center in Atlanta. Stephanie, I'm going to -- I'm going to start with you. What's happening right now where you are?

STEPHANIE ELAM, CNN CORRESPONDENT: Well, Jake, right now we can tell you that it's starting to warm up. We're starting to feel the heat coming that is expected all the way up to the coastline here. And as you can see, we are right on the Pacific Ocean which makes this fire interesting. Visually, overnight, it was stunning while we were here because as you look right here there's the Pacific coast highway that runs along the ocean. You've got some fire trucks coming out right now. And then right off the edge of the hillside over here we watched it burn down and actually jump over the fire -- jump over the PCH and towards the ocean.

We also were able to see today some firefighters out there fighting the brush. And just around the corner, actually, we were looking at them making sure that they're putting out fires, and also ensuring that power lines also stay safe. So, that was something that we see them doing throughout this region here -- Jake.

TAPPER: And how does California make sure it has resources to cover all the fires that sprout up around the state?

ELAM: Well, you know, it's interesting. Just looking at some of these trucks going by right now, you would think that they were all just Ventura County or Los Angeles County because of the proximity but they're not. They're coming from wide ranging areas of the state. Some even coming from Riverside County which is pretty far east as well. The way they do this throughout California and it's pretty much a unique system, but they will move fire trucks, troops, whatever they need to do to get people on the ground to fight a fire in one region.

And if another fire sprouts up in their region where they just came from, somebody will move into that territory to help take care of their properties there. So, they have a way of covering each other because as one firefighter told me yesterday, it's always fire season in southern California. And with seven fires burning in California right now overall, they just want to make sure they have all the resources to make sure they can put those fires out -- Jake.

TAPPER: Chad, what's fueling these fires? And talk a little bit more about how unusual it is to have these kinds of weather conditions in southern California this time of year.

CHAD MYERS, AMS METEOROLOGIST: Yes, it's a lack of rain. What should have been a 29-inch rainfall over the past 24 months was 14 inches. That's less than 50 percent of what you should have. So that means trees are dead, shrubs are dead, chaparral is just ready to burn. These are live pictures from KTLA. I know you were showing it a little bit ago. But I think it -- you don't understand how big these flames are, how hot these flames are until you get right to it.

Now, what I'm seeing here are shrubs burning, trees burning, that's the story of this fire, Jake. We haven't lost homes. Now, there are homes that are close to this fire break. Right here they are getting (INAUDIBLE) check down, they are bringing helicopters in because if you just keep -- then they're going to keep going over here. There are homes over here to the left where this fire is trying to get to so air assets in the way.

Here is where it all started. Here's L.A. We're talking almost 50 miles away right here in Camarillo. Put this into motion and we'll show you what happened. Yesterday, a spark, something right up here near the Ventura Highway. And as that came in, the sparks started, burned a bunch of these RVS near here. This is Camarillo Springs retirement area. Look how steep this is. This is a mountainous area. Wild land fire. An awful lot of just shrubbery out there. And it's all dry. It's all -- half of it's dead.

And what we're seeing now where I was just showing you that fire is this area here where there are a few homes. Most of it though is all the wild land area which -- just you're seeing just trees and shrubs burning. I heard a couple reports earlier that it's getting close to Malibu. Let me tell you, it's miles up the coast from Malibu. This has a long way to go to get to any real structures where you see a lot of population. And they will get it under control. We go from 90 degrees today to 75 tomorrow and even some showers, some rain possible on Sunday. That's the good news -- Jake.

TAPPER: All right, Chad. Thanks so much.

Here's what we're working on for this hour. the unemployment rate drops to 7.5 percent. That's the best rate since December 2008 but hold off on the celebrations. It's not all good news. We'll explain.

Plus, stepping up security in the wake of the Boston bombings. How officials at the Kentucky Derby plan to protect more than 100,000 people. Here's a hint, one thing you'll have to leave at home, big purses.

Also, he called a foul on a soccer player and ended up in a coma. This referee's family is hoping for a miracle after a teen-age player punched the ref in the head. That's coming up.

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TAPPER: Welcome back. We're watching a history-making day on Wall Street. The Dow has been bouncing around 15,000. It's the first time it's ever reached that high. The S&P 500 is also in record territory. The markets are reacting to a solid jobs report for April. The economy added 165,000 jobs last month, that's about 25,000 more than expected. The unemployment rate dipped from 7.6 percent to 7.5 percent. Good news, right? Let's take a closer look. And let's examine what does this all mean for you and your personal economy? Christine Romans has the story behind the numbers.

CHRISTINE ROMANS, CNN BUSINESS CORRESPONDENT: There's probably nothing more important to your money than your job whether you have one, whether you're moving up at it, and whether it's paying well, well enough to buy a house and send a kid to college. So, this is what we know about jobs today, 165,000 jobs created in the month of April. That is better than expected. And when you put it in perspective, you can see that things have been stronger this year than economists initially thought. Something was going on in February, 300,000 plus jobs created in February. And more created in March than we thought. When you average over the past year, 173,000 jobs created on average each month.

But, again, it's about your job, right? And whether you have a job that's paying well and that you're moving up at. So, let's talk about where the jobs are. Retail jobs, 29,000 jobs created there; wholesale trade and employment, 29,000 jobs; professional and business services, 73,000 jobs. Those tend to be the higher paid jobs. We want to continue to see those jobs increase. When you look overall at leisure and hospitality, 43,000 jobs created there. And also in health care, 19,000 jobs, that is a consistent performer for the economy, health care jobs every month.

But, again, be careful about wages. There are a lot of health care jobs that pay $19,000 or $20,000 a year, home care aides. There are other health care jobs that pay six figures on hospital doctors, and very highly skilled nurses. There's big differentiation there. Overall this is a strong report. This report says that the economy is slowly healing. The labor market is slowly healing. Those worries about a spring swoon may have been overblown. You want to see a lot more months like this--7.5 percent unemployment, before the recession it was 4.5 percent. We have a long way to go.

TAPPER: All right. Christine Romans. We have detailed maps for our roads, so why not map the human brain? We'll show you how scientists are looking inside our minds to find the secrets to our brains.

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TAPPER: President Obama is wrapping up a trip to Mexico. He's leaving as we speak. You see those images live of Mexico City of Air Force One. In Mexico he met with president Enrique Pena Nieto. He also spoke to college students in Mexico City. President Obama touched on business opportunities in his remarks fighting the war on drugs, gun control and comprehensive immigration reform.

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BARACK OBAMA, PRESIDENT OF THE UNITED STATES: It is critical that the United States recognize the need to reform our immigration system. Because we are a nation of laws, but we are also a nation of immigrants. Like every nation, we have a responsibility to ensure that our laws are upheld. We also know as a nation of immigrants, the immigration system we have in the United States right now doesn't reflect our values. It separates families when we should be reuniting them.

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TAPPER: Next stop is Costa Rica where Mr. Obama's expected to meet with U.S. embassy staff and Costa Rican President Laura Chinchilla.

President Obama's investing $100 million in taxpayer money to map the human brain, but what exactly are scientists looking for? Our Dr. Sanjay Gupta takes a tour of a brain map lab at UCLA run by Dr. Arthur Toga.

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SANJAY GUPTA, CNN MEDICAL CORRESPONDENT: How much progress in neuroimaging over the last ten years?

DR. ARTHUR TOGA, DIRECTOR, UCLA, NEUROIMAGING LAB: I think it's been amazing, because the technology to acquire detailed images of structure and function has been unprecedented. We can look at very small lesions, small as a millimeter or even smaller in a living human individual and we can relate not only what we see in terms of that person's anatomy but how it works.

GUPTA: The function.

TOGA: The function. How those cells are interacting with other regions in the brain to allow that person to behave.

GUPTA: This is pretty spectacular. What are we looking at?

TOGA: You're looking at tracks. You're looking at the fibers themselves that connect different regions. It allows us to see what region is connected to where and how much of a connection is there.

GUPTA: So when we talk about function like movements and sensation, we generally understand that, but what about the things a little more nebulous, self-awareness, happiness, pain. Is this going to help better identify those areas of the brain?

TOGA: I hope so. Obviously one has to start with a cruder map initially. It's just liking a map of the earth. We create a coordinate system, we find where the continents are. But now with our GPS systems we can find specific roads, we can even look up the amount of traffic on those roads. That's a very good analogy because it holds when we're studying the human brain as well. We have to first create the big map that show us the overall picture of how the brain is wired. Then we go down and look at the finer detail.

GUPTA: What does this mean for the average person?

TOGA: I think it's very important for us to undertake a challenge like this because we suffer from a number of neurological disorders, the population is getting older, there's an increased percentage of people with Alzheimer's disease for example. This kind of science lays the foundation for us to look for targeted therapies, and really is instructive in terms of improving the health and well-being of everyone.

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TAPPER: And Dr. Sanjay Gupta joins me now. Sanjay, welcome. This reminds me of the Human Genome Project. Can we expect similar results? Similar successes?

GUPTA: You know, I think that was a much more discreet sort of project. You remember, Jake, it took ten years, it cost several billion dollars and there was a specific goal at the end to map the human genome. When you talk about mapping the human genome, you're talking about matching 3 billion base pairs, for example. Here you have $100 million, so far less money. And there's trillions of neurons in the brain, Jake. So this whole idea of mapping the brain, it's in some ways a much more audacious thing. And I think less well- defined. Mapping the brain to what end is what a lot of scientists still want to know. We don't really know what some of the specific goals are.

TAPPER: What do they expect to find?

GUPTA: Well, you know, I would liken this in some ways to when we think about putting a man on the moon, there was an event of putting a man on the moon, but all the other sort of ancillary things we learned from that, how satellite technology works, some of the things we were showing in the piece, those things came about. They weren't necessarily the goal of the program at the time that it was started. And I think you could say similar thing here. They may learn more about how to diagnose Alzheimer's disease or things you can detect earlier. They may come up with new treatments as a result of those things. But right now it's about developing new technologies to better image and map the brain. That's where they're starting. Going to see where it goes from there.

TAPPER: Dr. Sanjay Gupta, thanks so much.

GUPTA: You got it, Jake.

TAPPER: If you're heading to the Kentucky Derby this weekend, big hats, yes. Big purses? No. Leave your camcorders and coolers at home. There will be heavy security in the wake of Boston bombings. That's coming up next.

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TAPPER: Welcome back to CNN. I'm Jake Tapper in Washington. Let's get up to speed on the latest developments in the investigation and fallout after the Boston bombings, the terrorist attacks at the marathon.

The funeral service for terror suspect Tamerlan Tsarnaev will be held in Worcester, Massachusetts, just outside Boston. That's according to the Worcester mayor. An uncle claimed the body yesterday. That act allows the Massachusetts medical examiner to release the official cause of death. We expect that will happen some time soon.

Meanwhile, a law enforcement official tells CNN the pressure cooker bombs used in the attacks were built in the small apartment in Cambridge that the dead suspect shared with his wife and child, in Cambridge, Massachusetts. The official also says captured suspect Dzhokhar Tsarnaev has told investigators that he and his brother decided to attack the Boston marathon only a day or two before the event. He says the initial plan was to carry out a suicide bomb attack at Boston's massive Fourth of July fireworks celebration, but their bombs were ready earlier than expected so they moved up the date. Again, that's what Dzhokhar is claiming.

There will be some changes at the Kentucky Derby tomorrow because of the Boston terror attack. Our Pam Brown looks at what authorities are doing to step up security and keep people safe at the run for the roses.

PAMELA BROWN, CNN CORRESPONDENT: It's one of horse racing's biggest events, the first of the triple crown races, a place to see and be seen. But this year's Kentucky Derby is happening just weeks after the Boston bombings. Security at Churchill Downs now understandably tightened.

JOHN ASHER, CHURCHILL DOWNS: Marathon bombing occurred and we were on the phone immediately with our law enforcement partners and had meetings the next day. We had to move pretty quickly because we were going to make any changes, if changes were warranted, we had to get the word out pretty quickly.

BROWN: Changes were made. In addition to the ban on backpacks in place since 9/11, the new security restrictions include no camcorders, cans, or coolers of any size. And women with purses larger than 12 inches will have to leave them at home for the big races. And the estimated 160,000 people going through the gates can expect to have more thorough bag inspections and magnetic wand searches.

ASHER: We hope not a single person that gets through the gate is surprised and trying to bring in something not allowed.

BROWN: 1,200 federal, state, and local officers will also be out in force, an increase of about 100 since the bombings.